Accepted identifier for a variable in PHP except:

Select one:

a. $_Puihaha

b. & Puihaha

c. $Pui_haha

d. $Puihaha

b. & Puihaha

Explanation:

PHP variables are supposed to start with a $ sign.

Other rules followed by PHP variables are:

Starting character in variable name (after $) must be letter or _.

Other characters in variable names can be letters, numbers or _.

a. $_Puihaha

c. $Pui_haha

d. $Puihaha

satisfy these rules.

Whereas, b. & Puihaha does not satisfy as it starts with '&'. Moreover it also contains an invalid space character in the variable.